16 é 
in the very midst of our field, where contact with the objects of our interest 
must be almost continuous. It seemed, consequently, clear that a house-boat | 
or so-called cabin boat of special construction, furnished as a biological 
laboratory, but with an equipment for minor experiments also, would meet | 
our needs far more precisely than a building on shore. | 
This laboratory boat, launched in April, 1896, was built at Havana from 
plans drawn up under my direction by Messrs. Gunn and McLane, of the 
architectural department of the University. A strong built hull of Wash- 
ington fir supports a deck 20x60 ft., upon which is a cabin 16x56 ft. In build-' 
‘ing the hull extraordinary pains were taken to. obtain a steady construction. | 
A three-inch solid bulk-head was run lengthwise through the middle. and two | 
keelsons divide the space between this central bulkhead and the gunwales. | 
Lateral strength was given by four series of diagonal braces, set as shown in | 
Plate VI, and placed every two feet, and by three hog-chains run from the 
bottom of each gunwale over the middle bulk-head. As a consequence, the | 
floor of the boat proved to be remarkably steady, no tremor being noticeable | 
in the use of the higher powers of the microscope on minute objects suspend- 
-ed in fluids. The interior of the hull is ventilated by means of four hatch- | 
ways with movable covers, two at each end of the deck. 
The cabin has six large windows on each side, made freely movable for. 
ventilation, and also transom ventilators above the windows. The roof ig 
penetrated by four large ventilators and walls and roof are made double, as 
a protection against the heat, by ceiling with Georgia pine. By virtue of 
these arrangements the laboratory rooms were remarkably comfortable during 
even the hottest weather of the year. | 
The interior of the cabin is divided into four rooms; an office and library at 
one end 11 feet and 6 inches by 16 feet, occupied by the Station staff; a main. 
laboratory 29 by 16 feet, primarily for visiting students and for the experi: - 
mental equipment; a kitchen 8 feet and 8 inches by 12 feet, with gasoline stove 
and other cook’s equipment, in which mid-day meals can be prepared for the 
Station force, and a small closet or store-room adjacent. The main laboratory 
is provided with tables, two to each window, and with shelving against the 
walls for books, note-boxes, specimens, etc., while down the center of the 
room is a sink table 3x22 feet, covered with zinc and furnished with a water 
supply for numerous small aquaria. A long overhead zinc-lined tank is sup- 
plied by iron piping, with a screw end outside the boat to which the discharge | 
pipe of a hand force-pump can be readily attached. Stopcocks and glass 
and rubber tubing make the necessary connections with the tanks and jars_ 
used for aquarium work, the overflow being carried off by drainage pipes 
which empty outside the hull. The space beneath the central table is enclosed” 
with doors and provided with shelves for general storage. : 
The boat has no motive power but is intended to be towed from place to | 
place as occasion requires. Our steam launch ‘‘Illini’’ proved, indeed, to have» 
sufficient power to transport this boat under ordinary circumstances. 
